DE10231356A1 - Water-absorbent, foam-like polymer structure - Google Patents

Abstract

The invention relates to a process for the production of water-absorbent, foam-like polymer structures, an aqueous composition (A) comprising DOLLAR A (A1) water, DOLLAR A (A2) one or more polymers which are at least DOLLAR A (a1) 55-100 % By weight of a polymerized, monoethylenically unsaturated, acid group-containing monomer or its salts, and on DOLLAR A (a2) 0-45% by weight of a polymerized, monoethylenically unsaturated, copolymerizable with (a1), DOLLAR A, the sum of the amounts by weight (a1) and (a2) is 100% by weight and where at least 31.5% by weight of the monomers, based on the total weight of the monomers (a1) and (a2), are acrylic acid or salts of acrylic acid, DOLLAR A ( A3) one or more crosslinking agents, DOLLAR A (A4) one or more blowing agents, DOLLAR A (A5) one or more surfactants, DOLLAR A (A6) and optionally other auxiliaries, DOLLAR A foamed and the foamed, aqueous composition is then heated at a temperature in a range from 50 to 300 ° C., so that the polymers (A2) are at least partially crosslinked and the water content (A1) is at most 15% by weight, based on the total weight of the resulting foam-like polymer structure, and a water-absorbent, foam-like polymer structure obtainable by this method, a water-absorbent, foam-like polymer structure, a composite comprising a water-absorbent, foam-like polymer structure and a substrate, method for ...

Description

The invention relates to a method for the production of a water-absorbing, foam-like polymer structure, one obtainable by this method water-absorbent, foam-like Polymer structure, a water-absorbing, foam-shaped polymer structure, a composite comprising a water-absorbent, foam-like polymer structure and a substrate, method for producing the composite, which by this procedure available associations, the use of the water-absorbent, foam-like polymer structure and chemical products.

Water absorbent polymers referred to as superabsorbents or superabsorbent polymers because they are able to multiply their own weight in watery liquids with the formation of hydrogels. Be in practice these superabsorbents, for example, in diapers for the absorption of Urine used. They have the property of the absorbed liquid withhold even under mechanical stress.

The use of superabsorbents happens mainly in powder form today. In the course of process simplifications there is a desire to use the superabsorbers in a fixed form, for example in a foamed one Integrate matrix. According to the state In technology, there are two different types of foamed systems.

The first type is a foamed matrix that contains pre-made superabsorbent granules. So described EP-A-0 427 219 Mixtures of superabsorbent polymers and latex foams. The foamed matrix serves to fix the superabsorbent granulate and to distribute liquids. However, the matrix itself only makes a very limited contribution to liquid absorption.

The second type is for foams, which themselves are made of superabsorbent material. For the production of such foams three different methods are described in the literature. these can either by polymerizing a monomer solution in a water-in-oil polymer dispersion (i), by foaming a monomer solution and subsequent Polymerization (ii) or by thermal foaming of a polymer with addition from inflatable or blowing agents (iii) are produced.

So describes WO 96/21680 and WO 96/21181 a foam produced by a process of type (i). In this process, a monomer mixture is emulsified aqueous Phase contains polymerized. The water acts as a placeholder for the later pores of the foam. The foams described in this document exhibit however, low retention.

WO 94/22502 describes one after one Method of type (ii) obtained foam based on partially neutralized Polyacrylates. The foam is made by foaming a monomer mixture with a water soluble Propellants such as Freon 1,1,2. The disadvantage of this Foams described document lies in their slow absorption rate.

WO 97/17397 are absorbent foams by foaming a monomer solution with blowing agents obtained by a method of type (ii). The disadvantage of in Foams described in this document are in their hardness and Brittleness. To process them, have to Plasticizers in the foams be incorporated.

US 4,394,930 describes absorbent polymer foams which have been produced by a process of type (iii). In the process described in this document, prefabricated superabsorbers, such as starch copolymers, are thermally foamed with the addition of blowing agents on a base such as a cellulose fleece or a polyethylene film. The foams obtained by this process are hard and not very flexible.

WO 880981 also describes absorbent Polymer foams, obtained by a method of type (iii). A terpolymer from ethyl acrylate, Na acrylate and Na methacrylate is in the presence of blowing agents such as Sodium bicarbonate, thermally foamed. Because of the low Have polyelectrolyte content however, the foams described in this document have a low retention.

In general, the object of the invention is in overcoming the disadvantages arising from the prior art.

Another based on this invention lying task is to provide absorbent polymer foams, that both in terms of retention and in terms of Absorption rate and absorption under a load have satisfactory properties.

Furthermore, the object of the invention is to provide absorbent foams which have a high degree of softness and flexibility, even though they consist of a uniform polymer, into which no pre-manufactured superabsorbent granulate has to be incorporated.

Furthermore, this invention lies the task of providing a method with which such foams through the use if possible less expensive Output connections and if possible without the use of halogenated hydrocarbons as blowing agents can be produced.

Finally, there is an object according to the invention in composites, especially hygiene articles and their components To provide, in addition to the suction properties, a high level of comfort have and especially not the user in his mobility limit.

• (A1) Wasser,
• (A2) ein oder mehrere Polymere, welche mindestens auf (α1) 55-100 Gew.-%, vorzugsweise 55-99,9 Gew.-% und besonders bevorzugt 70-90 Gew.-% einem polymerisierten, monoethylenisch ungesättigten, säuregruppenhaltigen Monomeren oder dessen Salz, sowie auf (α2) 0-45 Gew.-%, vorzugsweise 0,1-45 Gew.-% und besonders bevorzugt 10-30 Gew.-% einem polymerisierten, monoethylenisch ungesättigten, mit (α1) copolymerisierbaren Monomeren basiert, wobei die Summe der Gewichtsmengen (α1) und (α2) 100 Gew.-% beträgt und wobei mindestens 31,5 Gew.-% der Monomeren, vorzugsweise mindestens 50 Gew.-% und besonders bevorzugt mindestens 75 Gew.-%, jeweils bezogen auf das Gesamtgewicht der Monomeren (α1) und (α2), Acrylsäure oder Salze der Acrylsäure sind,
• (A3) einen oder mehrere Vernetzer,
• (A4) ein oder mehrere Blähmittel,
• (A5) ein oder mehrere Tenside,
• (A6) sowie gegebenenfalls weitere Hilfsstoffe

aufgeschäumt und die geschäumte, wässrige Zusammensetzung anschließend bei einer Temperatur in einem Bereich von 50 bis 300°C, vorzugsweise in einem Bereich von 100 bis 250°C erhitzt wird, so dass, vorzugsweise wodurch, die Polymere (A2) zumindest teilweise vernetzt und der Gehalt an Wasser (A1) auf höchstens 15 Gew.-%, bevorzugt auf höchstens 10 Gew.-% und besonders bevorzugt auf höchstens 5 Gew.-%, jeweils bezogen auf das Gesamtgewicht des entstehenden, schaumförmigen Polymergebildes und jeweils bestimmt nach der Ofenmethode gemäß ERT 430.1-99, eingestellt wird.The above objects are achieved by a method for producing water-absorbent, foam-like polymer structures, which comprises an aqueous composition (A)

• (A1) water,
• (A2) one or more polymers which comprise at least (α1) 55-100% by weight, preferably 55-99.9% by weight and particularly preferably 70-90% by weight of a polymerized, monoethylenically unsaturated, acid group-containing monomer or its salt, and based on (α2) 0-45% by weight, preferably 0.1-45% by weight and particularly preferably 10-30% by weight of a polymerized, monoethylenically unsaturated monomer which can be copolymerized with (α1) , the sum of the amounts by weight (α1) and (α2) being 100% by weight and wherein at least 31.5% by weight of the monomers, preferably at least 50% by weight and particularly preferably at least 75% by weight, in each case based on the total weight of the monomers (α1) and (α2), acrylic acid or salts of acrylic acid,
• (A3) one or more crosslinkers,
• (A4) one or more blowing agents,
• (A5) one or more surfactants,
• (A6) and optionally other auxiliaries

foamed and the foamed, aqueous composition is then heated at a temperature in a range from 50 to 300 ° C, preferably in a range from 100 to 250 ° C, so that, preferably thereby, the polymers (A2) at least partially crosslinked and the Water content (A1) to at most 15% by weight, preferably at most 10% by weight and particularly preferably at most 5% by weight, in each case based on the total weight of the foam-like polymer structure formed and in each case determined according to the oven method ERT 430.1-99.

In another embodiment of the method according to the invention the foam-like polymer structure obtained above can at least brought into contact again with at least one crosslinker become. The crosslinkers (A3) are preferred as crosslinkers. The further one Networking the foam-shaped The polymer structure is preferably carried out thermally, preferably in one Range from 50 to 300 ° C and particularly preferably in a range from 120 to 200 ° C. Especially crosslinking preferably takes place more strongly in the region of the surface of the foamy Polymer structure.

In a preferred embodiment of the method according to the invention are at least 50 mol%, preferably at least 90 mol% and particularly preferably at least 99.9 mol% of the monomers of the polymer (A2) water-soluble.

The monoethylenically unsaturated, containing acid groups Monomers (α1) can partially or completely, preferably be partially neutralized. They are preferably monoethylenic unsaturated, containing acid groups Monomers at least 25 mol%, particularly preferably at least 50 mole% and above also preferably neutralized to 50-90 mol%. The neutralization of the monomers (α1) can be done before or after the polymerization. Furthermore, neutralization with alkali metal hydroxides, alkaline earth metal hydroxides, Ammonia as well as carbonates and bicarbonates take place. Is next to it any other base conceivable that is water-soluble with the acid Salt forms. Also a mixed neutralization with different bases is conceivable. Neutralization with ammonia or is preferred with alkali metal hydroxides, particularly preferably with sodium hydroxide or with ammonia.

Preferred monoethylenically unsaturated, containing acid groups Monomers (α1) are acrylic acid, methacrylic acid, Ethacrylic acid, α-chloroacrylic acid, α-cyanoacrylic acid, β-methylacrylic acid (crotonic acid), α-phenylacrylic acid, β-acryloxypropionic acid, sorbic acid, α-chlorosorbic acid, 2'-methylisocrotonic acid, cinnamic acid, p-chlorocinnamic acid, β-stearyl acid, itaconic acid, citra acid , Mesaconic acid, glutaconic acid, aconitic acid, maleic acid, fumaric acid, tricarboxyethylene and maleic anhydride, being acrylic acid as well as methacrylic acid especially and acrylic acid about that are also preferred.

In addition to those containing carboxylate groups Monomers are monoethylenically unsaturated monomers containing acid groups (α1) of Another ethylenically unsaturated sulfonic or ethylenically unsaturated phosphonic prefers.

Ethylenically unsaturated sulfonic acid monomers are allylsulfonic acid or aliphatic or aromatic cal vinyl sulfonic acids or acrylic or methacrylic sulfonic acids are preferred. Preferred aliphatic or aromatic vinylsulfonic acids are vinylsulfonic acid, 4-vinylbenzylsulfonic acid, vinyltoluenesulfonic acid and stryrenesulfonic acid. Preferred acrylic or methacrylic sulfonic acids are sulfoethyl (meth) acrylate, sulfopropyl (meth) acrylate, 2-hydroxy-3-methacryloxypropylsulfonic acid and 2-acrylamido-2-methylpropαnsulfonic acid.

Furthermore, ethylenically unsaturated phosphonic acid monomers, like vinylphosphonic acid, allylphosphonic, vinylbenzylphosphonic, (Meth) acrylamidoalkylphosphonsäuren, Acrylamidoalkyldiphosphonsäuren, phosphonomethylated vinylamines and (meth) acrylicphosphonic acid derivatives prefers.

Preferred monoethylenically unsaturated, (α1) copolymerizable monomers (α2) are amides and nitriles of monoethylenically unsaturated carboxylic acids, such as, for example, acrylamide, methacrylamide and N-vinylformamides, dialkyldiallylammonium halides such as dimethyldiallylammonium chloride, vinylethyl allyl imidium chloride and , 1-vinyl-2-methylimidazole and N-vinylimidazolines such as N-vinylimidazoline, 1-vinyl-2-methylimidazoline, 1-vinyl-2-ethylimidazoline or 1-vinyl-2-propylimidazoline, which are in the form of the free bases, in quaternized form Form or as a salt can be used in the polymerization. Dialkylaminoalkyl acrylates and dialkylaminoalkyl methacrylates are also suitable, for example dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate and diethylaminoethyl methacrylate. Other preferred monomers (α2) are, for example, vinyl esters of saturated C ₁ -C ₄ -carboxylic acids such as, for example, vinyl formate, vinyl acetate or vinyl propionate, alkyl vinyl ethers with at least two carbon atoms in the alkyl group, such as for example ethyl vinyl ether or butyl vinyl ether, esters of monoethylenically unsaturated C ₃ -C ₆ - Carboxylic acids such as esters from monohydric C ₁ -C ₈ alcohols and acrylic acid, methacrylic acid or maleic acid, half esters of maleic acid, for example monomethyl maleate, and hydroxyalkyl esters of the monoethylenically unsaturated carboxylic acids mentioned, for example 2-hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypropyl methacrylate, hydroxypropyl methacrylate, hydroxypropyl methacrylate, and hydroxypropyl methacrylate Hydroxybutyl methacrylate, N-vinyl lactams such as N-vinyl pyrrolidone or N-vinyl caprolactam, acrylic acid and methacrylic acid esters of alkoxylated, monohydric, saturated alcohols, for example alcohols with 10 to 25 carbon atoms men who have been reacted with 2 to 200 moles of ethylene oxide and / or propylene oxide per mole of alcohol, and monoacrylic acid esters of polyethylene glycol or polypropylene glycol, the molecular weights of the polyalkylene glycols being able to be, for example, up to 2,000. Further suitable monomers (α2) are alkyl-substituted styrenes such as ethylstyrene or tert. Butylstyrene.

The production of the polymers (A2) can be carried out according to various polymerization processes known per se respectively. The radical polymerization is preferably more homogeneous Phase, especially in aqueous solution so-called gel polymerization. Precipitation polymerization is another option from organic solvents, such as from alcohols, or the suspension, emulsion or microemulsion polymerization. In special cases, instead of radical ones Polymerization also over Polymerizations proceeding with an ionic mechanism are useful. In the polymerization can in addition to the polymerization initiators, further adjuvants, such as, for example Chain regulators such as mercaptoethanol can be used.

As initiators to initiate the Polymerization can all initiators which form free radicals under the polymerization conditions are used, which is usually be used in the manufacture of superabsorbents. Also one Initiation of polymerization by exposure to electron beams on the polymerizable, aqueous Mixing of monomers is possible. However, the polymerization can also take place in the absence of initiators of the type mentioned above by exposure to high-energy radiation are triggered in the presence of photoinitiators.

Polymerization initiators are preferred Peroxides, hydroperoxides, hydrogen peroxide, persulfates, azo compounds as well as the so-called redox catalysts. Use is preferred water-soluble catalysts. In some cases it is advantageous to use mixtures of different polymerization initiators to use. Among these mixtures are those of hydrogen peroxide and sodium or potassium peroxodisulfate preferred, which is in every conceivable ratio can be used. Suitable organic peroxides are preferably acetylacetone peroxide, Methyl ethyl ketone peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-Amylperpivat, t-Butylperviat, t-Butylperneohexonat, t-Butylisobutyrat, t-butyl per-2-ethylhexenoate, t-butyl perisononanoate, t-butyl permaleate, t-butyl perbenzoate, t-butyl 3,5,5-tri-methylhexanoate and amyl perneodecanoate. Farther are preferred as polymerization initiators: azo compounds, such as 2,2'-azobis (2-amidinopropane) dihydrochloride, Azo-bis-amidinopropane dihydrochloride, 2,2'-azobis (N, N-dimethylene) isobutyramidindihydrochlorid, 2- (carbamoylazo) isobutyronitrile and 4,4'-azobis (4-cyanovaleric acid). The connections mentioned are in usual Amounts used, preferably in a range from 0.01 to 5; preferably from 0.1 to 2 mol%, in each case based on the amount of monomers to be polymerized.

The redox catalysts contain as oxidic component at least one of the above-mentioned per compounds and as reducing component preferably ascorbic acid, glucose, sorbose, manose, ammonium or alkali metal hydrogen sulfite, sulfate, thiosulfate, hyposulfite or sulfide, metal salts such as iron (II) ions or Silver ions or sodium hydroxymethyl sulfoxylate. Preferably as a reducing com component of the redox catalyst ascorbic acid or sodium pyrosulfite used. Based on the amount of monomers used in the polymerization, 1 × 10 ⁵ to 1 mol% of the reducing component of the redox catalyst and 1 × 10 ⁵ to 5 mol% of the oxidizing component of the redox catalyst are used. Instead of, or in addition to, the oxidizing component of the redox catalyst, one or more, preferably water-soluble, azo compounds can be used.

Is preferred for the production of Polymers (A2) a redox system consisting of hydrogen peroxide, sodium peroxodisulfate and ascorbic acid used. In general, azo compounds according to the invention are initiators preferred, with azo-bis-amidinopropane dihydrochloride particularly is preferred. As a rule, the polymerization with the initiators initiated in a temperature range of 30 to 90 ° C.

If you go through the polymerization Exposure to high-energy radiation is usually used so-called photoinitiators as initiators. It can be for example so-called α-splitters, H-abstracting systems or also azides. Examples of such Initiators are benzophenone derivatives such as Michlers ketone, phenanthrene derivatives, fluorene derivatives, Anthraquinone derivatives, thioxanthone derivatives, coumarin derivatives, benzoin ethers and their derivatives, azo compounds such as the radical formers mentioned above, substituted hexaarylbisimidazoles or acylphosphine oxides. Examples for azides are: (N, N-dimethylamino) ethyl 4-azidocinnamate, 2- (N, N-dimethylamino) ethyl 4-azidonaphthyl ketone, 2- (N, N-dimethylamino) ethyl 4-azidobenzoate, 5-azido-1-naphthyl-2- (N, N-dimethylamino) ethyl sulfone, N- (4-sulfonylazidophenyl) maleimide, N-acetyl-4-sulfonylazidoaniline, 4-sulfonylazidoaniline, 4-azidoaniline, 4-azidophenacyl bromide, p-azidobenzoic acid, 2,6-bis (p-azidobenzylidene) cyclohexanone and 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone.

In a preferred embodiment of the method according to the invention the polymers (A2) have a number average determined by GPC the molecular weight of at least 10,000 g / mol, preferred of at least 25,000 g / mol and more preferably at least 50,000 g / mol, preferably one determined by means of GPC Number average molecular weight of 10,000,000 g / mol, especially preferably of 5,000,000 g / mol is not exceeded.

In a further preferred embodiment of the method according to the invention will before foaming the watery Composition (A) in this a content of polymer (A2) of preferably 10 to 90 wt .-%, particularly preferably from 20 to 70 wt .-% and beyond preferably from 30 to 60% by weight, in each case based on the total weight the watery Composition (A). This setting is preferably carried out by dilution the watery Composition (A) with water.

Crosslinking agents (A3) preferred according to the invention are compounds that have at least two functional groups, those with functional groups of the monomers (α1) or (α2) in a condensation reaction (= Condensation crosslinker), in an addition reaction or in one Ring-opening reaction can react (Crosslinker class I), or polyvalent metal cations (crosslinker class II). The crosslinking class I compounds Crosslinking of the polymers by condensation reaction of the functional ones Groups reached while in the case of crosslinking class II, crosslinking electrostatic interaction of the polyvalent metal cation with the functional groups of the monomers (α1) or (α2) is achieved.

Examples of compounds of crosslinker class I include polyols, for example ethylene glycol, polyethylene glycols such as diethylene glycol, triethylene glycol and tetraethylene glycol, propylene glycol, polypropylene glycols such as dipropylene glycol, tripropylene glycol or tetrapropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,4-pentanediol, 1,6-hexanediol, 2,5-hexanediol, glycerol, polyglycerol, trimethylolpropane, polyoxypropylene, oxyethylene-oxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, pentaerythritol, polyvinyl alcohol and sorbitol, amino alcohols, ethanolamine, for example ethanol ethanol , Triethanolamine or propanolamine, polyamine compounds, for example ethylene diamine, diethylene triaamine, triethylene tetraamine, tetraethylene pentaamine or pentaethylene hexaamine, polyglycidyl ether compounds such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether; Glycerol polyglycidyl ether, Pentareritritpolyglycidylether, propylene glycol polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, Hexandiolglycidylether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, Phtahlsäurediglycidylester, Adipinsäurediglycidylether, 1,4-phenylene-bis (2-oxazoline), glycidol, polyisocyanates, preferably diisocyanates, such as 2,4-toluene diisocyanate and hexamethylene diisocyanate, polyaziridine compounds such as 2,2-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate], 1,6-hexamethylene-diethyleneurea and diphenylmethane-bis-4,4'-N, N'-diethyleneurea haloepoxides, for example epichlorohydrin and epibromohydrin and α-methylepichlorohydrin , Alkylene carbonates such as 1,3-dioxolan-2-one (ethylene carbonate), 4-methyl-1,3-dioxolan-2-one (propylene carbonate), 4,5-dimethyl-1,3-dioxolan-2-one, 4 , 4-dimethyl-1,3-dioxolan-2-one, 4-ethyl-1,3-dioxolan-2-one, 4-hydroxymethyl-1,3-dioxolan-2-one, 1,3-dioxan-2 -one, 4-methyl-1,3-dioxan-2-one, 4,6-dimethyl-1,3-dioxane -2-one, 1,3-dioxolan-2-one, poly-1,3-dioxolan-2-one, polyquaternary amines such as condensation products of dimethylamines and epichlorohydrin. Other compounds of crosslinker class I are polyoxazolines such as 1,2-ethylene bisoxazoline, crosslinkers with silane groups such as γ-glycidoxypropyltrimethoxysilane and γ-aminopropyltrimethoxysilane, oxazolidinones such as 2-oxazolidinone, bis- and poly-2-oxazoli dinones and diglycol silicates preferred.

Particularly preferred as a crosslinker crosslinker class I is ethylene carbonate.

The polyvalent metal cations of crosslinker class II are preferably derived from mono- or polyvalent cations, the monovalent in particular from alkali metals such as potassium, sodium, lithium, lithium being preferred. Preferred divalent cations are derived from zinc, beryllium, alkaline earth metals, such as magnesium, calcium, strontium, magnesium being preferred. Other higher-value cations which can be used according to the invention are cations of aluminum, iron, chromium, manganese, titanium, zirconium and other transition metals, and also double salts of such cations or mixtures of the salts mentioned. Aluminum salts and alums and their different hydrates such as, for. B. AlCl ₃ × 6H ₂ O, NaAl (SO ₄ ) ₂ × 12 H ₂ O, KAl (SO ₄ ) ₂ × 12 H ₂ O or Al ₂ (SO ₄ ) ₃ × 14-18H ₂ O.

Al ₂ (SO ₄ ) ₃ and its hydrates are particularly preferably used as crosslinking agents of crosslinking class II.

Preferred embodiments of the method according to the invention is a process in which crosslinkers of the following crosslinker classes or the following combinations of crosslinking classes: I, II, I II.

It is still according to the invention preferred that the crosslinker (A3) in an amount in a range of 0.001 to 10% by weight, preferably in a range of 0.01 to 5% by weight and particularly preferably in a range from 1 to 2.5% by weight, in each case based on the total weight of the aqueous composition (A) be used.

As a blowing agent (A4) in the method according to the invention preferably compounds used under the process conditions capable of gas evolution are. Preferred blowing agents are, for example, inorganic salts such as, for example, ammonium carbonate or azodicarbonate, or organic compounds that are among the Process conditions capable of decarboxylation, such as citric acid.

It is still according to the invention preferred that the blowing agent (A4) in an amount in a range of 0.1 to 20% by weight, preferably in a range from 1 to 15% by weight and particularly preferably in a range of 5 to 12 wt .-%, each based on the total weight the watery Composition (A) can be used.

Anionic, cationic, nonionic or ambivalent surfactants or mixtures thereof can be used as surfactants (A5). Both low molecular weight and polymeric surfactants can be used. Nonionic surfactants are, for example, addition products of alkylene oxides, in particular ethylene oxide, propylene oxide and / or buylene oxide, with alcohols, amines, phenols, naphthols or carboxylic acids. Addition products of ethylene oxide and / or propylene oxide with alcohols containing at least 10 carbon atoms are advantageously used as surfactants, the addition products containing 3 to 200 moles of ethylene oxide and / or propylene oxide added per mole of alcohol. The additive products contain the alkylene oxide units in the form of blocks or in a statistical distribution. Examples of nonionic surfactants are the addition products of% mol of ethylene oxide with 1 mol of tallow fatty alcohol, reaction products of 9 mol of ethylene oxide with 1 mol of tallow fatty alcohol and additone products of 80 mol of ethylene oxide with 1 mol of tallow fatty alcohol. Other commercially available nonionic surfactants consist of reaction products of oxo alcohols or Ziegler alcohols with 5 to 12 moles of ethylene oxide per mole of alcohol, in particular with 7 moles of ethylene oxide. Further commercially available nonionic surfactants are obtained by ethoxylating castor oil. For example, 12 to 80 moles of ethylene oxide are added per mole of castor oil. Other commercially available products are, for example, the reaction products of 18 mol ethylene oxide with 1 mol tallow fatty alcohol, the addition products of 10 mol ethylene oxide with 1 mol of a C ₁₃ / C ₁₅ oxo alcohol, or the reaction products with 7 to 8 mol ethylene oxide with 1 mol of a C ₁₃ / C ₁₅ oxo alcohol. Further suitable nonionic surfactants are phenol alkoxylates such as p-tert-butylphenol which has been reacted with 9 mol of ethylene oxide, or methyl ethers of reaction products of 1 mol of a C ₁ -C ₁₈ alcohol ₂ and 7.5 moles of ethylene oxide.

The surfactants described above can for example by esterification with sulfuric acid be converted into the corresponding sulfuric acid semiesters. The sulfuric acid half-esters are in the form of the alkali metal or ammonium salts as anionic Surfactants used. Suitable anionic surfactants are, for example Alkali metal or ammonium salts of half-esters of sulfuric acid from addition products of ethylene oxide and / or propylene oxide onto fatty alcohols, alkali metal or ammonium salts of alkylbenzenesulfonic acid or alkylphenol ether sulfates. Products of the type mentioned are commercially available.

Cationic surfactants are also suitable. Examples of this are the reaction products of quaternized with dimethyl sulfate 6.5 moles of ethylene oxide with 1 mole of oleylamine, distearyldimetyhlammonium chloride, Lauryl trimethyl ammonium chloride, cetyl pyridinium bromide and with dimethyl sulfate quaternized stearic acid triethanolamine ester.

The surfactants (A5) in the aqueous composition (A) are preferably in an amount in a range from 0.01 to 15% by weight, particularly preferably in a range from 0.05 to 10% by weight and beyond in a range of 0.1 to 5 wt .-%, each based on the weight of the aqueous Zu composition (A).

As auxiliary substances (A6) in the inventive method Stabilizers, thickeners, fillers or Cell nucleating agents or mixtures thereof are used.

Thickeners are used, for example Optimization of the foam structure and used to improve foam stability. It is achieved that the foam during the crosslinking of the polymers (A2) only marginally shrinking. All known for this purpose come as thickeners natural and synthetic polymers into consideration, the viscosity of a aqueous Systems increase significantly. This can be water-swellable or water-soluble synthetic or natural Trade polymers. Powdery superabsorbents are also used as thickeners suitable. A detailed overview of thickeners can be found, for example, in the publications by R. Y. Lochhead and W. R. Fron, Cosmetics & Toiletries, 108, 95-135 (May 1993) and M. T. Clarke, "Rheological Additive" in D. Laba (ed.) "Rheological Properties of Cosmetics and Toiletries ", Cosmetic Science and Technology Series, Volume 13, Marcel Dekker Inc., New York 1993, which is part of the Revelation form.

As fillers are preferred Chalk, concrete, talc, silica gel or silica, activated carbon, Pigments such as titanium dioxide and iron oxide or mixtures thereof are used become.

The auxiliaries (A6) are in the aqueous Composition (A) preferably in an amount in a range from 0.01 to 15% by weight, particularly preferably in a range from 0.05 to 10 wt% and above further preferably in a range from 0.1 to 5% by weight, in each case based on the weight of the aqueous composition (A) included.

In a preferred embodiment of the method according to the invention becomes the watery Composition (A) obtained by adding to that after the polymerization of the monomers (α1) and (α2) in an aqueous solution obtained, preferably aqueous polymer solution the crosslinkers, the blowing agents and optionally the other auxiliaries are added.

It is still according to the invention preferred that the aqueous Composition (A) a viscosity according to ASTM-D 1824/90 at 20 ° C of at least 100 mPas, preferably in a range from 100 to 500,000 mPa · s and particularly preferably in a range from 500 to 5,000 mPa · s.

In a preferred embodiment of the method according to the invention the composition (A) is foamed such that a foam liter weight in a range from 10 to 1,000 g / l, preferably in a range from 50 to 500 g / l and particularly preferably in a range of 80 to 250 g / l is obtained.

The aqueous composition is foamed preferably by mechanical influences, in particular shear, particularly preferably by vigorous stirring or mixing with mixing Air. However, it is also possible according to the invention, the composition by dispersing an inert gas in the form of fine gas bubbles froth. The introduction of gas bubbles in the aqueous composition (A) takes place, for example, with the help of whipping, shaking, stirring or Peitschvorrichtungen. It is also possible to change the composition by foaming that gases flow out of a liquid-covered opening or by taking advantage of turbulence in currents. Furthermore, the formation of lamellae on wires or Seven for this purpose can be used. These different methods can also may be combined with each other. Suitable as inert gases nitrogen, carbon dioxide, helium, neon and argon.

Heating the foamed composition is preferably done in an oven, a drying cabinet, with a be called Gas flow, by infrared radiation or by microwave radiation.

In a preferred embodiment of the method according to the invention is the foamed Before being heated, the composition is first converted into a shaped body. In a further preferred embodiment becomes the watery Composition before foaming transferred into a shaped body and subsequently in this molded body frothed. By subsequent heating the foamed Composition in this molded article can then water-absorbent, foam-like polymer structures with defined Spatial structure can be preserved.

In a further preferred embodiment of the method according to the invention becomes the surface of the absorbent, foam-shaped Polymer structure smoothed in a further process step, preferably at least partially smoothed. The smoothing takes place the surface preferably by moistening the surface with steam Temperatures in a range from 20 to 40 ° C and subsequent calendering. By moistening and then calendering the Pores in the surface area of the foam-like Polymer structure preferably only slightly compressed, but not completely locked.

The invention further relates to a water-absorbent, foam-like polymer structure, which is obtainable by the method described above.

• (β1) einen gemäß der hierin beschriebenen Testmethode bestimmte AUL (Absorbency under Load) von 0,9%er NaCl-Lösung bei einer Belastung von 0,3 psi von mindestens 10 g/g; bevorzugt von mindestens 13 g/g und besonders bevorzugt von mindestens 16 g/g;
• (β2) eine gemäß der hierin beschriebenen Testmethode bestimmte Absorptionsgeschwindigkeit von mehr als 1 g/g/sec, vorzugsweise mehr als 2 g/g/sec und besonders bevorzugt mehr als 3 g/g/sec;
• (β3) eine gemäß der hierin beschriebenen Testmethode bestimmte maximale Absorptionskapazität in einem Bereich von 20 bis 300 g/g, bevorzugt in einem Bereich von 30 bis 200 g/g und besonders bevorzugt in einem Bereich von 35 bis 100 g/g;
• (β4) eine gemäß der hierin beschriebenen Testmethode bestimmte CRC (Centrifugation Retention Capacity) in einem Bereich von 7,5 bis 100 g/g, bevorzugt in einem Bereich von 10 bis 80 g/g und besonders bevorzugt in einem Bereich von 15 bis 60 g/g;
• (β5) eine gemäß der hierin beschriebenen Testmethode bestimmte mittlere Porengröße in einem Bereich von 0,01 bis 2 mm, bevorzugt in einem Bereich von 0,1 bis 1 mm und besonders bevorzugt in einem Bereich von 0,2 bis 0,5 mm;
• (β6) ein gemäß der ERT 40.3-90 Testmethode bestimmtes mittleres Flächengewicht in einem Bereich von 60 bis 1200 g/m², bevorzugt in einem Bereich von 80 bis 800 g/m² und besonders bevorzugt in einem Bereich von 85 bis 500 g/cm².

In a preferred embodiment of the water-absorbent, foam-like polymer structure obtainable by the method according to the invention, this has at least one of the following properties

• (β1) an AUL (Absorbency under Load) determined according to the test method described herein 0.9% NaCl solution at 0.3 psi load of at least 10 g / g; preferably of at least 13 g / g and particularly preferably of at least 16 g / g;
• (β2) an absorption rate determined according to the test method described herein of more than 1 g / g / sec, preferably more than 2 g / g / sec and particularly preferably more than 3 g / g / sec;
• (β3) a maximum absorption capacity determined according to the test method described herein in a range from 20 to 300 g / g, preferably in a range from 30 to 200 g / g and particularly preferably in a range from 35 to 100 g / g;
• (β4) a CRC (centrifugation retention capacity) determined according to the test method described herein in a range from 7.5 to 100 g / g, preferably in a range from 10 to 80 g / g and particularly preferably in a range from 15 to 60 g / g;
• (β5) an average pore size determined according to the test method described herein in a range from 0.01 to 2 mm, preferably in a range from 0.1 to 1 mm and particularly preferably in a range from 0.2 to 0.5 mm;
• (β6) an average weight per unit area determined according to the ERT 40.3-90 test method in a range from 60 to 1200 g / m ² , preferably in a range from 80 to 800 g / m ² and particularly preferably in a range from 85 to 500 g / cm ² .

If the foam-like polymer structure is used in feminine hygiene articles, in particular sanitary napkins, a basis weight in the range from 60 to 200 g / m ^{2 is} preferred and in the range from 80 to 100 g / m ^{2 is} particularly preferred.

If the foam-like polymer structure is used in Bavarian hygiene articles, in particular diapers, a basis weight in the range from 400 to 1200 g / m ^{2 is} preferred and in the range from 550 to 800 g / m ^{2 is} particularly preferred.

Derived from the above properties resulting combinations of properties of two or more of these properties each represent preferred embodiments of the invention Polymeric structure. Also particularly preferred as embodiments according to the invention are polymer structures, which are referred to as letters or Character combinations shown properties or combinations of properties have: β1, β2, β3, β4, β5, β6, β1β2, β1β3, β1β4, β1β5, β1β6, β2β3, β2β4, β2β5, β2β6, β3β4, β3β5, β3β6, β4β5, β4β6, β2β3, β1β4 β1β2β3β4β5β6.

In a preferred embodiment by the inventive method available water-absorbent, foam-shaped Polymer structures have an open-cell structure, a closed-cell structure Structure or a mixed structure of open and closed cells, but preferably an open cell structure. Under one open cell structure is understood to mean a structure in which between adjacent pores of the foam a liquid exchange is possible, while in the case of a closed-cell structure, the individual pores from one another are isolated. With a mixed structure of open-cell and closed-cell Pores is a liquid exchange between some neighboring pores through common openings at least two adjacent pores possible, while others isolated from each other are, so that there is no fluid exchange between them through common openings in the pores. In a preferred embodiment of the method according to the invention available foamy Polymer structures are at least 25%, preferably at least 50% and above in addition, preferably at least 75% of the pores in a fluid exchange with at least one adjacent pore.

• (B1) 10 bis 99,9 Gew.-%, vorzugsweise 20 bis 70 Gew.-% und besonders bevorzugt 30 bis 60 Gew.-%, jeweils bezogen auf das Gesamtgewicht des Polymergebildes, eines oder mehrerer vernetzter Polymere mindestens basierend auf
• (γ1) 50 bis 99,99 Gew.-%, vorzugsweise 70 bis 99,8 Gew.-% polymerisierten monoethylenisch ungesättigten, säuregruppenhaltigen Monomeren oder deren Salze,
• (?2) 0 bis 45 Gew.-%, vorzugsweise 0,1 bis 27 Gew.-% polymerisierten monoethylenisch ungesättigten, mit (γ1) copolymerisierbaren Monomeren, sowie
• (γ3) 0,001 bis 5 Gew.-%, vorzugsweise 0,1 bis 3 Gew.-% eines oder mehrerer Vernetzer, wobei die Summe der Gewichtsmengen (γ1) bis (γ3) 100 Gew.-% beträgt und mindestens 31,5 Gew.-% der Monomeren, vorzugsweise mindestens 50 Gew.-% und besonders bevorzugt mindestens 75 Gew.-%, jeweils bezogen auf das Gesamtgewicht der Monomeren (γ1) und (γ2), Acrylsäure oder ein Salz davon sind,
• (B2) 0,01 bis 30 Gew.-%, vorzugsweise 0,01 bis 20 Gew.-% und besonders bevorzugt 0,1 bis 10 Gew.-% eines oder mehrerer Zusatzstoffe, bezogen auf das Gesamtgewicht des Polymergebildes sowie
• (B3) 0 bis 15 Gew.-%, bevorzugt 1 bis 10 Gew.-% und besonders bevorzugt 2 bis 5 Gew.-% Wasser, jeweils bezogen auf das Gesamtgewicht des Polymergebildes und jeweils bestimmt nach der Ofenmethode gemäß ERT 430.1-99,

wobei die Summe der Gewichtsmengen (B1) bis (B3) 100 Gew.-% beträgt und wobei das wasserabsorbierende, schaumförmige Polymergebilde mindestens eine der Eigenschaften (β1) bis (β6) aufweist, die im Zusammenhang mit dem durch das erfindungsgemäße Verfahren erhältlichen wasserabsorbierenden, schaumförmigen Polymergebilde genannt wurden.The invention also relates to a water-absorbent foam-containing polymer structure

• (B1) 10 to 99.9% by weight, preferably 20 to 70% by weight and particularly preferably 30 to 60% by weight, in each case based on the total weight of the polymer structure, based on at least one or more crosslinked polymers
• (γ1) 50 to 99.99% by weight, preferably 70 to 99.8% by weight, of polymerized monoethylenically unsaturated monomers containing acid groups or their salts,
• (? 2) 0 to 45 wt .-%, preferably 0.1 to 27 wt .-% polymerized monoethylenically unsaturated monomers copolymerizable with (γ1), and
• (γ3) 0.001 to 5% by weight, preferably 0.1 to 3% by weight, of one or more crosslinking agents, the sum of the amounts by weight (γ1) to (γ3) being 100% by weight and at least 31.5% by weight % of the monomers, preferably at least 50% by weight and particularly preferably at least 75% by weight, in each case based on the total weight of the monomers (γ1) and (γ2), acrylic acid or a salt thereof,
• (B2) 0.01 to 30% by weight, preferably 0.01 to 20% by weight and particularly preferably 0.1 to 10% by weight of one or more additives, based on the total weight of the polymer structure and
• (B3) 0 to 15% by weight, preferably 1 to 10% by weight and particularly preferably 2 to 5% by weight of water, in each case based on the total weight of the polymer structure and in each case determined by the oven method according to ERT 430.1-99,

the sum of the amounts by weight (B1) to (B3) being 100% by weight and the water-absorbing, foam-like polymer structure having at least one of the properties (β1) to (β6), which in connection with the water-absorbing material obtainable by the process according to the invention, foam-like polymer structures were called.

As additives (B2) are preferred which in connection with the method of manufacture according to the invention of a water-absorbent, foam-like polymer structure Contain surfactants (A5) and auxiliaries (A6).

In a preferred embodiment of the water-absorbent according to the invention, foamy Polymer structure has the same properties that already in connection with the method according to the invention available water-absorbent, foam-shaped Polymer structures were called.

In a further preferred embodiment of the water-absorbent, foam-like polymer structure according to the invention are as monomers (γ1) and (γ2) as well as a crosslinker (γ3) those monomers (α1), (α2) or Crosslinking agents (A3) are preferred, which are already in connection with the inventive method were called.

The invention also relates to a Composite comprising the foam-like polymer structure according to the invention as well a substrate. It is preferred that the foam-like polymer structure and the substrate are firmly connected. As substrates are Films made of polymers, such as polyethylene, polypropylene or polyamide, metals, fleeces, fluff tissues, fabrics, natural or synthetic fibers; or other foams preferred.

Since the in connection with the inventive method described, foamed Composition has a long service life, this can for example be applied to a substrate. The invention also relates to a method for producing a composite comprising the water-absorbing, foamy Polymer structures and a substrate, which in connection with the method according to the invention described foamed Composition with at least part of the surface of a Substrate is brought into contact with the foamed composition subsequently contacted substrate at a temperature in a range from 50 to 300 ° C, preferably a range from 100 to 250 ° C is heated, so that, preferred whereby the polymers (A2) at least partially crosslinked, the content of water (A1) at most 15% by weight, preferably to at most 10% by weight and particularly preferably based on at most 5% by weight, in each case on the total weight of the resulting foam-like polymer structure and each determined according to the furnace method according to ERT 430.1-99 and the resulting, foam-like Polymer structures immobilized on at least part of the substrate surface (1st procedure).

In a preferred embodiment this method according to the invention the foamed composition is brought into contact with the substrate surface by applying the composition, preferably by brushing, Doctoring or pouring, on the substrate surface in a 0.1 to 10 mm, preferably in a 1 to 8 mm and particularly preferably in a 2 to 4 mm thick layer. It is still according to the invention preferred that the foamed Composition in defined areas, for example by the Use of stencils or screens, applied to the substrate becomes. In a further preferred embodiment of this method is the foamed Composition applied to fluff layers and the fluff layers thus with the foamed Impregnated composition, so that the fluff after networking is an integral part of the Is foam. As substrates in connection with this process are films made of polymers, such as polyethylene, polypropylene or Polyamide, metals, fleeces, fluff, tissues, fabrics, natural or synthetic fibers, or other foams preferred.

A composite containing the water-absorbing, foamy Polymer structures can also be obtained in that at least part of the surface of the water-absorbent, foam-like polymer structure with at least part of the surface brought into contact with a substrate and then the polymer structure at least part of the substrate surface is immobilized (2. Method). The water-absorbent, foam-like Polymerge can form in the form of polymer structures with a defined spatial structure, as they are in connection with the manufacturing method according to the invention of a water-absorbent, foam-like polymer structure were used. However, it is also possible to use defined polymer structures Space structure from larger blocks of the Cut out or saw out the polymer structure.

• (δ1) Aneinanderdrücken des Substrates und des wasserabsorbierenden, schaumförmigen Polymergebildes mit einem spezifischen Druck von mindestens 0,1 N/cm, bevorzugt von mindestens 0,5 N/cm und besonders bevorzugt von mindestens 1 N/cm oder Aneinanderdrücken des Substrates und des schaumförmigen Polymergebildes mit einem Druck von mindestens 0,1 N/cm², bevorzugt von mindestens 0,5 N/cm² und besonders bevorzugt von mindestens 1 N/cm²;
• (δ2) Erhitzen des mit dem schaumförmigen Polymergebilde in Kontakt gebrachten Substrates auf eine Temperatur in einem Bereich voν 50 bis 300°C, bevorzugt eine einem Bereich von 100 bis 250°C.

In a preferred embodiment of this method, the immobilization of the polymer structure on the substrate surface is carried out by at least one of the following process steps:

• (δ1) pressing the substrate and the water-absorbent, foam-like polymer structure together with a specific pressure of at least 0.1 N / cm, preferably at least 0.5 N / cm and particularly preferably at least 1 N / cm, or pressing the substrate and the foam-shaped together Polymer structure with a pressure of at least 0.1 N / cm ² , preferably of at least 0.5 N / cm ² and particularly preferably of at least 1 N / cm ² ;
• (δ2) heating the substrate brought into contact with the foam-like polymer structure to a temperature in a range from 50 to 300 ° C., preferably in a range from 100 to 250 ° C.

Preferred embodiments of this method are processes that are carried out by the following process steps or Combinations of process steps are marked δ1, δ2, δ1δ2. The conditions of Process steps δ1, δ2 preferably chosen so that the foam structure is not destroyed or after the Treatment according to the above described method can form again.

In a preferred embodiment this inventive method takes place immobilizing the water-absorbent, foam-like polymer structure according to the invention on the substrate surface by calendering or by ironing of the substrate brought into contact with the polymer structure. Preferably a protective layer on the side of the substrate that is not in contact with the polymer structure. As Substrates in connection with this process are thermoplastic fabrics, preferably at least partially fusible fabrics, such as Polyethylene films, preferred.

It is still according to the invention preferred that by the method of manufacture according to the invention of a composite containing at least sandwich-like structures two layers of the water-absorbent, foam-like polymer structure and at least two substrate layers can be obtained by using one first process step one from the water-absorbing, foam-like polymer image (P1) and a substrate (S1) existing composite either after the 1st or 2. Establishes the process in a second process step a layer of the foamed Composition with that surface of the substrate (S1) that the contact area between the polymer structure (P1) and the substrate (S1), in contact and, as described in the 1st method, with formation a water-absorbing, foam-like polymer structure (P2) immobilized and in a third process step that surface of the water-absorbent, foam-shaped Polymer structure (P2), which is the contact area between the polymer structure (P2) and the substrate (S1), and, as described in the second procedure, on the Immobilized substrate (S2). These process steps can, depending by number of desired Layers can be repeated any number of times.

The invention also relates to the the method according to the invention Composites obtained for the production of a composite. Below are the fibers, in particular fluff-containing composites sandwich-like Structures preferred that are used as core in hygiene items can be.

Furthermore, this concerns Invention the use of the water-absorbent, foam-like polymer structures according to the invention or the composites according to the invention in chemical products. The chemical products are preferably fibers, foils, films, cables, sealing materials, fluid receiving Hygiene articles, wound coverings, carriers for plant and fungal growth regulators Means, additives for building materials, Packaging materials and floor additives.

The invention also relates to chemical Products containing the water-absorbent, foam-like polymer structures according to the invention or the composites according to the invention. Preferred chemical products are fibers, foils, films, cables, Sealing materials, liquid absorbent Hygiene articles, wound coverings, carriers for plant and fungal growth regulators Means, additives for building materials, Packaging materials and floor additives.

Among the above chemical Products prefer hygiene products. These are again Sanitary napkins, baby diapers, adult incontinence articles, including Diapers are particularly preferred.

In a particularly preferred embodiment according to the invention, the composite is a diaper. The constituent parts of the diaper, which are different from the absorbent, foam-like polymer structure according to the invention, represent the substrate of the composite. In a preferred embodiment, the diaper contains a core described above. In this case, the constituent parts of the diaper, which are different from the core, constitute the substrate of the composite. In general, a composite used as a diaper comprises a water-impermeable lower layer, a water-permeable, preferably hydrophobic, upper layer and a layer containing the absorbent, foam-like polymer according to the invention is arranged between the lower layer and the upper layer. This layer containing the absorbent, foam-like polymer structure according to the invention is preferably a previously described core. The lower layer can have all materials known to the person skilled in the art, with polyethylene or polypropylene being preferred. The top layer can likewise contain all suitable materials known to the person skilled in the art, with preference being given to polyesters, polyolefins, viscose and the like which give such a porous layer which ensure adequate liquid permeability of the top layer. In this regard, the revelation in US 5,061,295 , US Re. 26,151, US 3,592,194 . US 3,489,148 such as US 3,860,003 directed. These disclosures are hereby introduced as a reference and are therefore considered part of the disclosure.

The invention is now based on limiting test methods and examples explained in more detail.

TEST METHODS

DETERMINATION OF THE FOAM LITER WEIGHT

For this, a predetermined amount was given Composition (A) in a 1 l measuring cylinder of known weight foamed up to the 1 l mark.

DETERMINATION OF ABSORPTION UNDER LORD (AUL)

To determine fluid intake under pressure (AUL) 160 mg of the water-absorbent, foam-like polymer structure, that corresponded to the dimensions of the plastic cylinder, in a plastic cylinder weighed in with sieve cloth in the bottom and with a defined weight , which exerts a pressure of 0.3 psi on the polymer structure exercises. The cylinder unit is weighed and placed on a filter paper covered with 0.9% NaCl solution impregnated Filter plate placed. The filter plate is up to its top edge in the liquid. protruding liquid is to be avoided and the fluid level check after 20 and 40 minutes. After a suction time of The cylinder unit is weighed back for 1 hour and removed from the scale the AUL calculates. The AUL is defined as that per gram of the polymer structure amount of weight of NaCl solution taken up.

DETERMINATION OF ABSORPTION SPEED

To determine the absorption rate the water-absorbent, foam-like polymer structure from the polymer structure a round test surface with a diameter of 40 mm punched out and balanced. In a petri dish of diameter 5 g of a 0.9% sodium chloride solution stained with methylene blue are weighed out 60 mm and just on a white one Document provided. The test area is from a height of 10 mm in the with the solution filled Petri dish dropped vertically. The time from the moment of Hitting the test surface up to the liquid surface at the time the liquid Completely from the test area is stopped. A five-fold determination is carried out and the uptake speed of the structures is given in g / g / sec.

DETERMINATION OF MAXIMUM ABSORPTION CAPACITY

A 0.9% NaCl solution was used to determine the maximum absorption capacity of the water-absorbing, foam-like polymer structure. From a water-absorbent, foam-like polymer structure, a piece of the polymer structure is punched out with a weight of about 1 g and a thickness of about 1 to 5 mm, weighed (W1) and welded into a tea bag. The tea bag is placed in the test solution for 30 minutes and weighed after a draining time of 10 minutes (W2). A tea bag without water-absorbing polymer, which is also placed in the test solution and whose weight is also determined after it has dripped (W3), is run as a blank value. The maximum absorption capacity was given in g / g and calculated as follows:

DETERMINATION OF CENTRIFUGATION RETENTION CAPACITY (CRC)

The teabag test was carried out to determine the retention of the foam-like structure. A 0.9% NaCl solution was used as the test solution. A piece of the polymer structure with a weight of approximately 1 g and a thickness of approximately 1 to 5 mm, is weighed out (W1) and welded into a tea bag from a water-absorbing, foam-like polymer structure. The tea bag is placed in the test solution for 30 minutes and then spun in a centrifuge (23 cm diameter, 1,400 rpm) for 3 minutes and weighed again (W2). A tea bag without water-absorbing polymer, the weight of which is also determined after spinning (W3), is run as a blank value. The CRC value was given in g / g and calculated as follows:

DETERMINATION OF THE MEDIUM pore size

The mean pore size was determined by means of a magnifying glass and a ruler Diameter of about 100 different pores of a relaxed surface of the cut foamy Polymeric structure determined and from the measurement values thus obtained Mean was formed. This determination was repeated on 10 cut surfaces. The average of these averages corresponds to the average pore size.

DETERMINATION OF THE MEDIUM PORE DENSITY

The average pore density was determined in which by means of a magnifying glass and a ruler in an area of 1 cm × 1 cm of the surface of a foamy Polymer structure the number of pores recognizable in this area was determined. To this end, the total number of pores was approximately 10 areas were determined and the mean value obtained from the measured values obtained in this way calculated. This corresponds to the average pore density of the diameter determined from about 20 different pores and from the thus obtained Measured values the mean value was determined. This mean corresponds the average pore size.

example 1

Preparation of a polyacrylic acid solution, 3.5% Na-neutralized, molecular weight approx. 120,000 g / mol).

weights: 225.74 g acrylic acid 8.79 g 50% aqueous sodium hydroxide solution 677.00 g deionized water 0.66 g mercaptoethanol 1.17 g 6% aqueous ascorbic acid solution

8.34 G 35% hydrogen aqueous hydrogen peroxide solution 6.00 G 20% aqueous hydroxylamine

Be in a face grinding flask Acrylic acid, sodium hydroxide and 477.00 g of deionized water. It will be an hour Nitrogen through the solution passed and to 30 ° C. heated. With stirring Mercaptoethanol, ascorbic acid solution and 1.45 g hydrogen peroxide solution added, after which the temperature of the solution rises to about 85 ° C. You leave Stir for 30 min at a bath temperature of 80 ° C and then add 6.00 g of hydroxylamine hydrochloride solution and 6.89 g of hydrogen peroxide solution added. The heating bath is switched off and 200.00 g of deionized Water added so that an aqueous 25% polymer solution arises.

Example 2

Preparation of an acrylic acid-hydroxyethyl methacrylate copolymer, 3.5% Na neutralized, Molecular weight approx.145,000 g / mol.

weights: 217.72 g acrylic acid 8.03 g hydroxyethyl methacrylate 8.48 g 50% aqueous sodium hydroxide solution 677.00 g deionized water 0.66 g mercaptoethanol 1.17 g 6% aqueous ascorbic acid solution 8.34 g 35% aqueous hydrogen peroxide solution 6.00 g 20% aqueous hydroxylamine hydrochloride solution

Be in a face grinding flask Acrylic acid, Hydroxyethyl methacrylate and sodium hydroxide solution in 477.00 g deionized Given water. Nitrogen is passed through the solution for one hour and heated to 30 ° C. Under stir mercaptoethanol, ascorbic acid solution and 1.45 g of hydrogen peroxide solution are added, after which the temperature of the solution to approx. 100 ° C increases. You leave Stir for 2 hours at a bath temperature of 80 ° C and then give 6.00 g of hydroxylamine hydrochloride solution and 6.89 g of hydrogen peroxide solution and lets Stir for another hour at a bath temperature of 80 ° C. The Heating bath is switched off, and 200.00 g of deionized water are added, so a watery 25% polymer solution is formed.

Example 3

Preparation of an acrylic acid-butyl acrylate copolymer 3.5% Na neutralized, molecular weight approx.420,000 g / mol.

weights: 213.97 g acrylic acid 11.77 g butyl acrylate 8.34 g 50% aqueous sodium hydroxide solution 677.00 g deionized water 0.44 g mercaptoethanol 1.17 g 6% aqueous ascorbic acid solution 7.15 g 35% aqueous hydrogen peroxide solution 6.00 g 20% aqueous hydroxylamine hydrochloride solution

Be in a face grinding flask acrylic acid and sodium hydroxide solution added to 477.00 g of deionized water. It will be nitrogen for an hour through the solution passed and to 30 ° C. heated. With stirring mercaptoethanol, ascorbic acid solution and 1.24 g of hydrogen peroxide solution are added, and simultaneously dropped butyl acrylate within three minutes. The temperature of the solution rises quickly to approx. 96 ° C. You leave Stir for 2 hours at a bath temperature of 80 ° C and then give 6.00 g of hydroxylamine hydrochloride solution and 5.91 g hydrogen peroxide solution and lets Stir for another hour at a bath temperature of 80 ° C. The Heating bath is switched off, and 200.00 g of deionized water are added, so a watery, highly viscous 25% polymer solution arises.

Example 4

Production of a water-absorbing, foam-like polymer structure according to the invention. 33.35 g Polymer from Example 1 0.4 g Stokal SR (Gebrüder Langefeld, Krefeld) 0.5 g potassium stearate 0.5 g Glucopon 225 CS UP (Henkel KGaA, Düsseldorf) 12.18 g 9.71% sodium hydroxide solution 16.71 g 15.34% potassium hydroxide solution 0.15 g Denacol Ex 810 (Nagase Kaseikogyo, Japan) 8.22 g citric acid monohydrate 4.0 g ethylene

are put together and opened using a Krupps 3 mixer for three minutes. The resulting foam is spread over an area of 0.1 m ² and to a height of 0.2 cm and heated for 15 minutes at 220 ° C. in a forced-air drying cabinet. The resulting structure has the following characteristics: Table 1

Example 5

Production according to the invention of a water-absorbent, foam-like polymer structure.

Analog to Example 4, 33.35 g Copolymer processed into water-absorbent, foam-like polymer structures. The copolymer is prepared analogously to Example 1, wherein the corresponding proportion in the molar ratio given in Table 2 of acrylic acid has been replaced by a comonomer.

Table 2

Example 6

Production of a water-absorbent, foamy Polymer structure. Analogously to Example 4, 33.35 g of copolymer are added water-absorbent, foam-shaped Processed polymer structures. The copolymer is produced analogous to Example 2, with the result being that given in Table 3 molar ratio has been discontinued.

Table 3

Example 7

Manufacture of a water-absorbent, foamy Polymer structure. Two polymers, produced analogously to example 2, are mixed in the ratio given in Table 4 and analogous to Example 4 processed.

Table 4

Example 8

Production of a water-absorbent, foamy Polymer structure with alternative crosslinkers. The polymer becomes analog prepared for Example 2, butyl acrylate after the Polymerization is added dropwise within 3 minutes. The production the water-absorbing, foam-like polymer structure takes place analogous to example 4. Denacol Ex 810 is varied against that in the Table 5 specified crosslinkers.

Table 5

Example 9

Production of a water-absorbent, foamy Polymer structure. Analogously to Example 4, 33.35 g of copolymer (97 moles of acrylic acid : 3 mol butyl acrylate) to form a water-absorbing, foam-like polymer structure processed.

Table 6

Example 10

The production of a polymer structure according to the invention from an acrylic acid-butyl acrylate copolymer (97 mol: 3 mol) prepared according to Example 3, but with quantity of mercaptoethanol is reduced to 0.22 g. Analogous to example 4, 33.35 g of copolymer become a water-absorbing, foam-like polymer structure processed.

Table 7

Example 11

The production of a polymer structure according to the invention made of an acrylic acid polymer prepared according to Example 1, but with the amount of mercaptoethanol is reduced to 0.44 g. Analogously to Example 4, 33.35 g of copolymer processed into a water-absorbing, foam-like polymer structure.

Table 8

Example 12

The production of a polymer structure according to the invention made of an acrylic acid polymer prepared according to Example 1, but with the amount of mercaptoethanol is reduced to 0.22 g. Analogously to Example 4, 33.35 g of copolymer processed into a water-absorbing, foam-like polymer structure.

Table 9

Example 13

Production of a water-absorbent, foamy Polymer structure from an acrylic acid-butyl acrylate copolymer (97 mol: 3 mol) with alternative crosslinkers. The polymer from example 3 is used. The structures are produced analogously to Example 4. Denacol Ex810 is replaced by the one in the table specified crosslinker.

Table 10

Example 14

Production of a water-absorbent, foamy Polymeric structure from an acrylic acid polymer, prepared according to Example 1, but with the amount of mercaptoethanol is reduced to 0.44 g. The structures are produced analogously for example 4. Denacol Ex 810 is exchanged for that in the Crosslinker specified in the table.

Table 11

Example 15

Production according to the invention of a water-absorbing, foam-like polymer structure from acrylic acid polymers with different surfactant additives. 33.35 g Polymer from Example 1 0.4 g Stokal SR 0.5 g Surfactant as indicated in the table 33.42 g 15.34% potassium hydroxide solution 0.15 g Denacol Ex 810 8.22 g citric acid monohydrate 2.0 g ethylene

are put together and by means of of a Krupps 3 mixer for three Minutes opened. The resulting foam is on an area of 0.1 m2 and to a height of 0.2 cm and heated for 15 min at 220 ° C in a circulating air oven.

The resulting polymer structure has following characteristics:

Table 12

Example 16

Production of a water-absorbent, foamy Polymeric structure from acrylic acid polymer with a waterproof Back.

33.35 G polymer from example 1 0.4 G Stokal SR

0.5 G potassium stearate 0.5 G glucopon 225 CS UP (Henkel, Düsseldorf) 12.18 G 9.71 % sodium hydroxide solution  16.71 G 15.34% owned potassium hydroxide 0.15 G Denacol Ex 810 8.22 G citric acid monohydrate 4.0 G ethylene 1.00 Estekoll HL 50/200 1.00 Sarpifan PA 308 A (Stockhausen GmbH & Co. KG, Krefeld)

are put together and by means of of a Krupps 3 mixer for three Minutes opened. The resulting foam is on an area of 0.1 m2 and to a height of 0.2 cm and heated for 15 min at 220 ° C in a circulating air oven. The polymer structure obtained is placed on a polyethylene film (PE film) and placed between siliconized paper strips for 10 minutes an iron until complete The structure adhered to the foil.

Table 13

Example 17

100 g of a prepared according to Example 4 Foams were even with a solution sprayed from 15 g of water and 1.5 g of ethylene carbonate. After the ethylene carbonate solution is in the foam over a Hour evenly distributed the foam loaded with ethylene carbonate was over 60 minutes at 180 ° C post-crosslinked and dried. It became a post-crosslinked foam with properties according to Table 14 receive.

Table 14

Claims (16)

A method of making water-absorbent, foamy Polymer structures, an aqueous Containing composition (A) (A1) water, (A2) a or more polymers, which at least on (α1) 55-100 % By weight of a polymerized, monoethylenically unsaturated, containing acid groups Monomers or its salt as well (α2) 0-45% by weight of a polymerized, monoethylenically unsaturated, with (α1) based on copolymerizable monomers, where the sum of Amounts by weight (α1) and (α2) Is 100% by weight and wherein at least 31.5% by weight of the monomers, based on the Total weight of monomers (α1) and (α2), acrylic acid or salts of acrylic acid are, (A3) one or more crosslinkers, (A4) one or several blowing agents, (A5) one or more surfactants, (A6) and, if appropriate, others excipients frothed and the foamed, aqueous Composition afterwards heated at a temperature in a range of 50 to 300 ° C is, so that the polymers (A2) at least partially crosslinked and the water content (A1) to at most 15% by weight, based on the total weight of the foam-like polymer structure formed, is set. The method of claim 1, wherein the polymer (A2) is a number average of molecular weight of at least 10,000 g / mol. The method of claim 1 or 2, wherein the foamed composition has a foam liter weight of 10 to 1,000 g / l. Method according to one or more of claims 1 to 3, wherein the surface of the absorbent, foam-shaped Polymer structure is smoothed in a further process step. A water-absorbent, foam-like polymer structure available after a method according to claim 1 to 4. The water-absorbent, foam-like polymer structure according to claim 5, wherein the polymer structure has at least one of the following properties: (β1) an AUL (Absorbency under Load) of 0.9% NaCl solution under a load of 0.3 psi of at least 10 g / G; (ß2) an absorption rate of more than 1 g / g / sec; (β3) a maximum absorption capacity in a range of 20 to 300 g / g; (β4) a CRC (Centrifugation Retention Capacity) in a range from 7.5 to 100 g / g; (β5) an average pore size in a range of 0.01 to 2 mm; (β6) an average pore density in a range from 60 to 1200 g / m ² . Containing a water-absorbent, foam-like polymer structure (B1) 20 to 99.99% by weight, based on the total weight of the polymer structure, one or several crosslinked polymers based at least on (γ1) 50 to 99.9% by weight of a polymerized monoethylenically unsaturated, containing acid groups Monomers or its salt, (γ2) 0 to 45% by weight of a polymerized monoethylenically unsaturated, with (? 1) copolymerizable monomers, and (? 3) 0.001 to 5 wt .-% of one or more crosslinkers, the sum of the amounts by weight (γ1) to (γ3) 100 % By weight and at least 31.5% by weight of the monomers, based on the total weight of the monomers (γ1) and (γ2), acrylic acid or are a salt of it, (B2) 0.01 to 30% by weight of one or several additives, based on the total weight of the polymer structure such as (B3) 0 to 15% by weight of water, based on the total weight of the polymer structure, where the sum of the weight amounts (B1) to (B3) is 100% by weight and wherein the water-absorbent, foam-like polymer structure at least has one of the properties defined in claim 6 (β1) to (β6). Composite comprising a water-absorbing, foam-like polymer structure according to claims 5 to 7 and a substrate. A method of making a composite according to claim 8, wherein a foamed A composition as defined in claims 1 to 3, with at least part of the surface a substrate is brought into contact with the foamed composition subsequently contacted substrate at a temperature in a range of 50 to 300 ° C is heated so that the polymers (A2) are at least partially crosslinked, the water content (A1) to at most 15% by weight, based on the total weight of the foam-like polymer structure formed, adjusted and the resulting foam-like polymer structure at least part of the substrate surface is immobilized. The method of claim 9, wherein the substrate is a film Polymers, such as made of polyethylene, polypropylene or Polyamide, a metal, a fleece, a fluff a tissue, a fabric, a natural or is synthetic fiber or another foam. The method of claim 4 or 10, wherein the application the foamed, aqueous Composition can be used on the substrate stencils. A method of making a composite according to claim 8, wherein at least part of the surface of a water-absorbent, foamy Polymer structure according to one of claims 5 to 7 with at least part of the surface brought into contact with a substrate and then the polymer structure at least part of the substrate surface is immobilized. The method of claim 12, wherein the substrate is a thermoplastic sheet is. Composite available by a method according to a or more of the claims 9 to 13. Use of a water-absorbent, foam-like polymer structure according to one or more of claims 5 to 7 or a composite according to claim 8 or 14 in chemical products. Chemical products containing a water and aqueous liquids absorbent, foam-like Polymer structure according to one or more of claims 5 to 7 or a composite according to claim 9 or 14.